1. Field of the Invention
The present invention relates to a saddle riding type vehicle which is a three-wheeled or four-wheeled automotive vehicle including a right wheel and a left wheel arranged at opposite sides of a vehicle body to be movable up and down, and is capable of making turns by leaning the vehicle body. Such a saddle riding type vehicle can appropriately illuminate directions of its movement with a headlight when making turns by leaning the vehicle body.
2. Description of the Related Art
A motorcycle has heretofore been proposed that has an onboard headlight that is rotatable, when making a turn, to illuminate the traveling surface ahead in the turning direction. When making a turn by leaning the vehicle body to the right, for example, the headlight is rotated to illuminate an area to the right and forward. When making a turn by leaning the vehicle body to the left, the headlight is rotated to illuminate an area to the left and forward as disclosed in Japanese Unexamined Patent Publication H6-115397 and Japanese Unexamined Patent Publication No. 2006-315674, for example.
Japanese Unexamined Patent Publication H6-115397 discloses a motorcycle having a headlight, a drive mechanism for rotating the headlight about an optical axis, various sensors, a control switch, and a controller for controlling the drive mechanism. The sensors include a lean angle sensor and a speed sensor, and the control switch is a dimmer switch. Based on detection results from the sensors and an input signal from the control switch, the controller rotates the headlight when predetermined conditions are fulfilled, such as when a vehicle speed is at a certain speed or faster, a lean angle is at a certain angle or larger, and the headlight is directed downward.
Further, the controller derives an angular speed from a lean angle, and increases the rotating speed and amount of rotation of the headlight when the angular speed is relatively high. As a result, no delay occurs in responding to a sudden position change of the vehicle body, and the headlight can appropriately illuminate a range of view to be seen by the rider.
Japanese Unexamined Patent Publication No. 2006-315674 discloses a three-wheeled automotive vehicle having a headlight, a right wheel and a left wheel arranged at opposite sides of a front portion of a vehicle body, and a suspension for supporting the right wheel and left wheel. The suspension can incline the right wheel and left wheel in response to leaning of the vehicle body. The suspension includes a plurality of beams and arms. A cross beam which is a member of the suspension is maintained substantially horizontal irrespective of inclinations of the right wheel and left wheel. The headlight is fixedly supported by this cross beam.
Therefore, even when the vehicle body leans relative to a traveling surface, the positional relationship of the headlight and the traveling surface remains constant. As a result, the headlight can continue illuminating the traveling surface in the direction of movement of the three-wheeled automotive vehicle.
However, the conventional vehicles with such constructions have the following drawbacks and disadvantages.
With the motorcycle described in Japanese Unexamined Patent Publication H6-115397, the relatively expensive lean angle sensor increases the manufacturing cost of the vehicle.
In addition, the lean angle sensor cannot detect positions of the motorcycle accurately or properly. Particularly where a traveling surface is sloping, an increased gap is created between an actual position of the motorcycle and a result of detection by the lean angle sensor. The controller controls the drive mechanism based on such a detection result from the lean angle sensor. As a result, there can be a possibility, for example, of the headlight being rotated when the motorcycle is not actually making a turn. Conversely, the headlight may not rotate although the motorcycle is making a turn. Thus, with the motorcycle according to Japanese Unexamined Patent Publication H6-115397, it is difficult to illuminate a traveling surface in the direction of movement properly with the headlight in various situations such as when the traveling surface is not horizontal.
With the three-wheeled automotive vehicle according to Japanese Unexamined Patent Publication No. 2006-315674, the cross beam which must be maintained horizontal restricts flexibility of the structure of the suspension. Since the headlight is fixed to the cross beam, the illuminating direction of the headlight cannot be varied flexibly. It is difficult to illuminate the direction of movement properly in various situations.